The present invention relates to automatic dishwashers and, more particularly, an improved apparatus to dispense an additive, such as a detergent, into the washer at the appropriate time.
Conventional domestic dishwashers operate through a preselected series of timed wash and rinse cycles, during which additives are added to the wash or rinse water at appropriate times. For example, detergent may be dispensed at different times during the wash cycle or operation and rinse agent dispensed during the rinse operation. Apparatus to automatically dispense additives, such as detergent and rinse agent for example, are well known. U.S. Pat. No. 4,159,657--Nelson et al, assigned to General Electric Company illustrates and describes one such dispensing mechanism and is incorporated herein by reference. As set forth therein, the dispenser is installed in the door of the dishwasher. It includes a main part in the form of an additive storage reservoir or container formed integrally with the inner wall of the door. The reservoir is supplied with additive when the door is in its open (horizontal) position. A closure device, comprising a cover and handle, is then rotated over the reservoir and the cover is drawn tight against the container by manual operation of the handle. The apparatus also includes a spring driven, timer controlled mechanism to open the cover for dispensing the additive at a preselected time during operation of the machine. In order to tightly seal the container a sealing ring extends around the periphery of the container and the cover includes a gasket which is mounted on the underside of the cover and firmly engages the sealing ring when the cover closes. This apparatus works well and provides a good vapor seal to protect the additive from the water being sprayed about the inside the washer. However the cover and gasket assembly includes a number of parts and requires a number of assembly steps In addition, the gasket requires a clorination processing step to reduce its coefficient of friction so that it will not "stick" to the ring as the cover opens and closes. This all adds to the cost and manufacturing time of the apparatus.
It is therefore an object of this invention to provide an improved dispensing apparatus which is constructed from a minimum number of parts while providing consistent performance.
It is another object of this invention to provide such an apparatus including an unitary cover that does not require a sealing gasket.